This application is based on Japanese Patent Applications No. 2000-128070 and No. 2000-128071, which are incorporated herein by reference.
1. Field of the Invention
The present invention relates to a weather strip attached to, for example, a peripheral portion of a door opening of a vehicle or the like.
2. Description of the Related Art
Generally, such a weather strip of this kind is provided with trim portions each having a substantially U-shape in section, and hollow seal portions each formed on a one-side outer surface of the trim portion. Then, at least one holding lip is formed on the inner side surface of the trim portions so as to project thereon. In the condition that the trim portions have been attached to a peripheral flange of a door opening of a vehicle body, the holding lip is brought into pressure contact with a side surface of the flange and another side surface of the flange is substantially brought into pressure contact with the opposite inner side surface of the trim portions so that the weather strip is held in an attachment state.
Conventionally, in such a weather strip, trim portions and hollow seal portions of straight-lined portions corresponding to the upper and lower sides and the front and rear sides of the door opening, are formed of a soft and elastic material such as EPDM rubber or the like by extrusion molding. Further reinforce inserts are embedded in trim portions. On the other hand, a trim portion and a hollow seal portion of each of four corner portions corresponding to the four corner portions of the door opening are formed by the following two molding methods for example.
That is, according to one of those two methods, of the trim and hollow seal portions each extruded linearly and integrally, only a part of the hollow seal portion is removed by cutting out. Then, in the condition that the trim portion is bent correspondingly to the cut-out portion of the hollow seal portion along to the corner portion, then, a hollow seal portion is formed on a side surface of the bent portion of the trim portion by mold molding to reproduce the hollow seal portion of the cut-out portion.
On the other hand, according to the other method, each of the trim and hollow seal portions extruded linearly and integrally is cut into predetermined length so as to form two extruded portions. The ends of two extruded portions are disposed in a mold so as to have a predetermined positional relationship. Then, mold molding material such as EPDM rubber is injected into a cavity of the mold. Therefore, the trim and hollow seal portions for a corner portion are formed into a curve by mold molding so as to connect the cut end portions of those extruded portions with each other in the curve, respectively.
When such mold molding method is performed, conventionally, the molded hollow seal portion and the molded trim portion are formed of a single material of EPDM solid rubber having a predetermined hardness by injection molding method at one time in consideration of the flexibility of the molded hollow seal portion and the shape retaining property of the molded trim portion as well as the economical efficiency in forming.
Recently, in serious consideration of the functions of the respective portions, there is proposed a weather strip in which a molded hollow seal portion is formed of a soft and elastic material, such as thermoplastic elastomer for example TPO, or such as a rubber material for example EPDM rubber, having a high flexibility and elasticity while a molded trim portion is formed of a hard material such as PE, PP, or the like, so as to have a substantially U-shape in section and bent shape. Then, the hard material has a predetermined elastic deformability but it is higher in hardness than the soft and elastic material of the molded hollow seal portion to retain its shape.
In such a proposed weather strip, however, since the molded trim portion of each of the corner portions is formed of the hard material as mentioned above and further since the molded trim portion is formed by mold molding, it is difficult to provide a holding lip on the inner side surface of the molded trim portion such as on the inner side surface of an extruded trim portion in each straight-lined portion. This is because the holding lip is to be undercut when the molded trim is molded thus it is impossible to form the holding lip by mold molding. Accordingly, in the case where a peripheral flange of a door opening of a vehicle body is inserted between the opposite side walls of the trim portion in each of the straight-lined portions and each of the corner portions so that the weather strip is attached to the peripheral portion of the door opening, there has been a problem that it is difficult to hold the flange fixedly between the parallel opposite side walls of the molded trim portion of each of the corner portions.
In the case where the thickness of the side walls of the molded trim portion is substantially the same as that of the side walls of the extruded trim portion, the distance between the opposite side walls of the molded trim potion becomes larger than that of the side walls of the extruded trim portion due to a space where the holding lip is to be provided. Therefore the molded trim portion can not hold the flange of the vehicle body. Meanwhile, it has been proposed that the thickness of the side walls of the molded trim portion is set to be so large that the distance between the opposite side walls of the molded trim portion is substantially the same as the thickness of the flange of the vehicle body. In this case, however, another problem is caused that the flange could be unable to be inserted between the opposite side walls of the molded trim portion due to the rigidity of the side walls of the molded trim portion.
On the other hand, in each of the above-mentioned methods for forming the corner portion, a core member is used for molding the molded hollow seal portion. To draw out the core member from the molded hollow seal portion after molding the molded hollow seal portion, an opening portion is provided along one edge of the molded hollow seal portion. In addition, the opening portion is formed to leave a flap portion at the edge of the molded hollow seal portion so that an end surface of the flap portion can abut against a one-side outer surface of the molded trim portion. This is to prevent the molded hollow seal portion of the corner portion from being deformed flatly when the door is brought into pressure contact with the molded hollow seal portion in the condition that the weather strip has been attached to the door opening.
However, since the flap portion is formed in such a proposed weather strip, the flap portion is to be undercut in accordance with the direction in which the core member is straight drawn out. It is therefore difficult to automate the work of drawing out the core member from the molded hollow seal portion of the corner portion. Thus, there has been a problem that it is necessary for a worker to draw out the core member carefully and curvedly by hand while elastically deforming the flap portion to the outside. In addition, there has been a problem that excessive force is apt to be applied to the flap portion to thereby damage the molded hollow seal portion of the corner portion when the core member is drawn out. Thus, there has been a problem that the manufacturing cost of the weather strip is increased.
The present invention is developed in consideration of the foregoing problems. It is an object of the present invention to provide a weather strip in which a peripheral flange of an opening in a vehicle body or the like can be held fixedly between the opposite side walls of a molded trim portion of each corner portion, and the corner portions can be kept stably in an attachment state.
Further, another object of the present invention to provide a weather strip in which a core member can be drawn out easily from a molded hollow seal portion of a corner portion when the molded hollow seal portion is molded, so that the manufacturing cost of the weather strip can be reduced.
In order to achieve the above object, according to the first aspect of the invention, there is provided a weather strip comprising: straight-lined portions each of which has a trim portion having a substantially U-shape in section and a hollow seal portion; and corner portions each of which is formed between the straight-lined portions so as to connect the straight-lined portions, and each of which has a molded trim portion having a substantially U-shape in section and composed of a hard material and a molded hollow seal portion composed of a soft and elastic material; wherein an opening width between opposite side walls of the molded trim portion of the corner portion is formed to be narrower than an opening width between opposite side walls of the trim portion of each of the straight-lined portions.
According to the invention, in the case where a peripheral flange of a door opening of a vehicle or the like is inserted between the opposite side walls of the trim portion in each straight-lined portion and between the opposite side walls of the molded trim portion in each corner portion and the weather strip is attached to the peripheral flange of the door opening, the opening width between the opposite side walls of the molded trim portion in each corner portion is enlarged. Thus, the opposite side walls are brought into pressure contact with the opposite side surfaces of the flange or the like. As a result, even if no holding lip is provided on the inner surfaces of the side walls of the molded trim portion of each corner portion, the flange or the like can be held fixedly between the opposite side walls of the molded trim portion so that the corner portion can be kept stably in an attachment state.
Preferably, a projection is formed on an inner surface of at least one of the opposite side walls of the molded trim portion of the corner portion.
Consequently, the opening width between the opposite side walls of the molded trim portion in each corner portion can be made narrower. Thus, the force with which the flange or the like is held between the opposite side walls can be enhanced further.
Further preferably, the projection is formed on an inner surface of one of the opposite side walls of the molded trim portion of the corner portion correspondingly to a holding lip provided on an inner surface of one of the side walls of the trim portion of each of the straight-lined portions.
Consequently, on the same side as the holding lip provided in the trim portion of each of the straight-lined portions, strong holding force can be given to the flange or the like by the projection of the molded trim portion of each of the corner portions. Thus, the stability in attachment can be enhanced in the corner portions.
Further preferably, the opposite side walls of the molded trim portion of the corner portion are formed so that the opening width between the opposite side walls of the molded trim portion of the corner portion is enlarged by deforming the corner portion from a predetermined curved state to a larger curved state.
Consequently, in the case where the weather strip is attached to a flange of a door opening of a vehicle body, the straight-lined portions are brought into close relationship so as to deform and bend the corner portions on a large scale. That is, the corner portions are deformed so that the curvature thereof is increased (or the curvature radius thereof is reduced). Thus, the opening width between the opposite side walls of the trim portion can be enlarged. As a result, the flange can be inserted easily between the opposite side walls.
Further preferably, the opposite side walls of the molded trim portion of the corner portion are formed so that the opposite side walls are deformed and restored to have a predetermined opening width when the corner portion is restored to the predetermined curved state from the larger curved state.
Consequently, when the flange has been inserted between the opposite side walls of the molded trim portion of each corner portion, the corner portion is brought into a predetermined curved state. Thus, the opening width opening between the opposite side walls of the molded trim portion of each corner portion is reduced so that the opposite side walls of the molded trim portion are brought into pressure contact with the opposite side surfaces of the flange. Accordingly, the molded trim portion of each corner portion is fixedly attached to and held in the corner portion of the flange. It is therefore possible to attach the weather strip to the peripheral portion of the door opening of the vehicle body easily and surely.
In order to achieve the above object, according to the second aspect of the invention, there is provided a weather strip comprising curved corner portions each having a molded trim portion and a molded hollow seal portion, the molded trim portion having a substantially U-shape in section, the molded hollow seal portion being formed on a one-side outer surface of the molded trim portion, the molded hollow seal portion having an opening portion for drawing out a core member for forming the molded hollow seal portion, the opening portion being formed at an end of the molded hollow seal portion so that a flap portion is left correspondingly to the one-side outer surface of the molded trim portion while the end surface of the flap portion is capable of abutting against the one-side outer surface; wherein at least one notch portion is formed in a part of the flap portion so as to facilitate deformation of the flap portion when the core member is straight drawn out.
In this weather strip, when the core member is straight drawn out from the molded hollow seal portion of the corner portion, the flap portion is apt to be elastically deformed in the direction in which the core member is straight drawn out. Accordingly, the core member can be drawn out from the molded hollow seal portion easily without applying excessive force to the flap portion. As a result, the work of molding the molded hollow seal portion of the corner portion can be automated while the molded hollow seal portion of the corner portion can be prevented from being damaged. Thus, the manufacturing cost of the weather strip can be reduced.
Preferably, as the notch portion, a plurality of notch portions are formed.
In this weather strip, when the core member is straight drawn out from the molded hollow seal portion of the corner portion, the flap portion is elastically deformed more easily. Thus, the core member can be straight drawn out more easily.
Further preferably, the notch portion or portions are formed in accordance with the number of core members.
In this weather strip, in the case where there are a plurality of core members, excessive force is appropriately prevented from being applied to the flap portion when the core members are straight drawn out, respectively.
Further preferably, the notch portion is formed in a portion in which the end of the core member abuts against the flap portion for the first time when the core member is straight drawn out, respectively.
In this weather strip, excessive force is more surely prevented from being applied locally to the flap portion when the core members are straight drawn out from the molded hollow seal portion of the corner portion.
Further preferably, the molded hollow seal portion is formed of thermoplastic elastomer.
Particularly, in the case where the molded hollow seal portion of the corner portion is formed of a material of thermoplastic elastomer such as TPO, or the like, which is lower in stretchability than a rubber material, the foregoing operations are performed markedly.